 The waste products from broiler slaughtering and carcass processing, such as feathers, blood, bones, and meat trimmings, make up approximately 30% of the original live body weight of the birds. These byproducts can be used as a source of animal protein in diets for poultry. In this study, we determined the biochemical properties of the fermented protein additives produced by short-term thermal treatment and subsequent enzymatic hydrolysis of collagen and keratin-containing poultry wastes. The dry protein additive based on the keratin-containing wastes featured average moisture content 4.57%, crude protein content 86.52%, crude fat content 2.25%, ash content 2.04%, the respective parameters in the dry additive based on the collagen containing wastes after high-temperature treatment and enzymatic hydrolysis were 2.57%, 45.4%, 23.29%, and 24.04%. The digestibility of the dry keratin and collagen-based additives. This article was authored by V. G. Volik, D. U. Ismayova, V. S. Lukashenko, and others. We are article.tv, links in the description below.